Nancy,
I spoke with Eric about Victor’s global slope stability analysis and he seemed to have several concerns with it. I am unsure how to proceed. Any suggestions?
Thanks,
Clay Barnett, P.E.
Town Engineer
Town of Addison
16801 Westgrove Drive
Addison, TX 75001-2818
Office: (972) 450-2857
-----Original Message-----
From: Clay Barnett
Sent: Tuesday, March 23, 2010 2:05 PM
To: 'Christiansen, Eric'
Cc: Nancy Cline
Subject: RE: Vitruvian Park - Geotechnical Issue
Eric,
Attached is what we received from Victor on the park design. Once you have had an opportunity to review it, please contact me.
I have also asked UDR to get with Geotel on these items.
Thanks,
Clay Barnett, P.E.
Town Engineer
Town of Addison
16801 Westgrove Drive
Addison, TX 75001-2818
Office: (972) 450-2857
-----Original Message-----
From: Christiansen, Eric [mailto:echristiansen@halff.com]
Sent: Monday, March 22, 2010 12:15 PM
To: Clay Barnett
Cc: Nancy Cline
Subject: Vitruvian Park - Geotechnical Issue
Importance: High
Clay,
There is one issue that came to light late Friday that will require the assistance of the geotechnical engineer. One of our engineers contacted Geotel to discuss lateral soil pressures
for the abutment walls. We are trying to reduce the load on our abutment walls by using select or granular fill in lieu of on-site clays. Instead of responding to our question, we were
informed that the walls would need to be analyzed for global slope stability. To be fair, the Geotel soil report (at the end of section 6.3) mentions this analysis should be accomplished
for slopes greater than 10' or retaining walls bearing on slopes. While our project doesn't meet the description perfectly, it's apparent that we won't be able to get our question answered
until Geotel completes some additional analysis.
Since the report was written to UDR, it is likely that UDR paid for the report. If that is true, please ask UDR to see that the following items are accomplished:
· Global stability analysis of abutments at Ponte, Bella, and the Southern Pedestrian Bridge (as required)
· Clarification of the 110 pcf lateral load for retaining walls
o Is this an at-rest load for on-site clays (as is assumed)?
o Can this be reduced by using select fill or a granular fill?
We regret this is being addressed at this stage of the design process, but we didn't anticipate this would become an issue for walls on drilled shafts. Since we don't believe the outcome
will significantly affect our design, we will continue to work on the project while we await an answer from Geotel. Should you have any questions or concerns regarding this matter, please
feel free to contact me directly.
Sincerely,
Eric Christiansen
Eric S. Christiansen, P.E., SECB, LEED AP
Senior Structural Engineer
HALFF ASSOCIATES, INC.
1201 North Bowser Road
Richardson, Texas 75081
Phone 214-346-6284
Fax 214-739-0095
Cell 972-955-2996
www.halff.com